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      1 /*
      2  * Copyright (C) 2013, The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *     http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #include "suggest/policyimpl/dictionary/header/header_policy.h"
     18 
     19 namespace latinime {
     20 
     21 // Note that these are corresponding definitions in Java side in FormatSpec.FileHeader.
     22 const char *const HeaderPolicy::MULTIPLE_WORDS_DEMOTION_RATE_KEY = "MULTIPLE_WORDS_DEMOTION_RATE";
     23 // TODO: Change attribute string to "IS_DECAYING_DICT".
     24 const char *const HeaderPolicy::IS_DECAYING_DICT_KEY = "USES_FORGETTING_CURVE";
     25 const char *const HeaderPolicy::LAST_UPDATED_TIME_KEY = "date";
     26 const char *const HeaderPolicy::LAST_DECAYED_TIME_KEY = "LAST_DECAYED_TIME";
     27 const char *const HeaderPolicy::UNIGRAM_COUNT_KEY = "UNIGRAM_COUNT";
     28 const char *const HeaderPolicy::BIGRAM_COUNT_KEY = "BIGRAM_COUNT";
     29 const char *const HeaderPolicy::EXTENDED_REGION_SIZE_KEY = "EXTENDED_REGION_SIZE";
     30 const int HeaderPolicy::DEFAULT_MULTIPLE_WORDS_DEMOTION_RATE = 100;
     31 const float HeaderPolicy::MULTIPLE_WORD_COST_MULTIPLIER_SCALE = 100.0f;
     32 
     33 // Used for logging. Question mark is used to indicate that the key is not found.
     34 void HeaderPolicy::readHeaderValueOrQuestionMark(const char *const key, int *outValue,
     35         int outValueSize) const {
     36     if (outValueSize <= 0) return;
     37     if (outValueSize == 1) {
     38         outValue[0] = '\0';
     39         return;
     40     }
     41     std::vector<int> keyCodePointVector;
     42     HeaderReadWriteUtils::insertCharactersIntoVector(key, &keyCodePointVector);
     43     HeaderReadWriteUtils::AttributeMap::const_iterator it = mAttributeMap.find(keyCodePointVector);
     44     if (it == mAttributeMap.end()) {
     45         // The key was not found.
     46         outValue[0] = '?';
     47         outValue[1] = '\0';
     48         return;
     49     }
     50     const int terminalIndex = min(static_cast<int>(it->second.size()), outValueSize - 1);
     51     for (int i = 0; i < terminalIndex; ++i) {
     52         outValue[i] = it->second[i];
     53     }
     54     outValue[terminalIndex] = '\0';
     55 }
     56 
     57 float HeaderPolicy::readMultipleWordCostMultiplier() const {
     58     const int demotionRate = HeaderReadWriteUtils::readIntAttributeValue(&mAttributeMap,
     59             MULTIPLE_WORDS_DEMOTION_RATE_KEY, DEFAULT_MULTIPLE_WORDS_DEMOTION_RATE);
     60     if (demotionRate <= 0) {
     61         return static_cast<float>(MAX_VALUE_FOR_WEIGHTING);
     62     }
     63     return MULTIPLE_WORD_COST_MULTIPLIER_SCALE / static_cast<float>(demotionRate);
     64 }
     65 
     66 bool HeaderPolicy::writeHeaderToBuffer(BufferWithExtendableBuffer *const bufferToWrite,
     67         const bool updatesLastUpdatedTime, const bool updatesLastDecayedTime,
     68         const int unigramCount, const int bigramCount, const int extendedRegionSize) const {
     69     int writingPos = 0;
     70     if (!HeaderReadWriteUtils::writeDictionaryVersion(bufferToWrite, mDictFormatVersion,
     71             &writingPos)) {
     72         return false;
     73     }
     74     if (!HeaderReadWriteUtils::writeDictionaryFlags(bufferToWrite, mDictionaryFlags,
     75             &writingPos)) {
     76         return false;
     77     }
     78     // Temporarily writes a dummy header size.
     79     int headerSizeFieldPos = writingPos;
     80     if (!HeaderReadWriteUtils::writeDictionaryHeaderSize(bufferToWrite, 0 /* size */,
     81             &writingPos)) {
     82         return false;
     83     }
     84     HeaderReadWriteUtils::AttributeMap attributeMapTowrite(mAttributeMap);
     85     HeaderReadWriteUtils::setIntAttribute(&attributeMapTowrite, UNIGRAM_COUNT_KEY, unigramCount);
     86     HeaderReadWriteUtils::setIntAttribute(&attributeMapTowrite, BIGRAM_COUNT_KEY, bigramCount);
     87     HeaderReadWriteUtils::setIntAttribute(&attributeMapTowrite, EXTENDED_REGION_SIZE_KEY,
     88             extendedRegionSize);
     89     if (updatesLastUpdatedTime) {
     90         // Set current time as a last updated time.
     91         HeaderReadWriteUtils::setIntAttribute(&attributeMapTowrite, LAST_UPDATED_TIME_KEY,
     92                 time(0));
     93     }
     94     if (updatesLastDecayedTime) {
     95         // Set current time as a last updated time.
     96         HeaderReadWriteUtils::setIntAttribute(&attributeMapTowrite, LAST_DECAYED_TIME_KEY,
     97                 time(0));
     98     }
     99     if (!HeaderReadWriteUtils::writeHeaderAttributes(bufferToWrite, &attributeMapTowrite,
    100             &writingPos)) {
    101         return false;
    102     }
    103     // Writes an actual header size.
    104     if (!HeaderReadWriteUtils::writeDictionaryHeaderSize(bufferToWrite, writingPos,
    105             &headerSizeFieldPos)) {
    106         return false;
    107     }
    108     return true;
    109 }
    110 
    111 /* static */ HeaderReadWriteUtils::AttributeMap
    112         HeaderPolicy::createAttributeMapAndReadAllAttributes(const uint8_t *const dictBuf) {
    113     HeaderReadWriteUtils::AttributeMap attributeMap;
    114     HeaderReadWriteUtils::fetchAllHeaderAttributes(dictBuf, &attributeMap);
    115     return attributeMap;
    116 }
    117 
    118 } // namespace latinime
    119